One of the drawbacks of the kilonova r-process site is that it starts to take place at a relatively long time after the NS-NS formation, i.e., the gravitational waves timescale. Studies show the need for some r-process nucleosynthesis events in the early Galaxy (e.g., [1]}) and more generally in the early Universe. [2]}, for example, argue that because of this long delay to NS-NS merger the kilonova scenario cannot account for the r-process abundance of old stellar populations in ultrafaint dwarf galaxies. On the other hand, some studies find solutions to the problems of the kilonova scenario (e.g., [3]}, [4]}, [5]}, [6]}).
